Aromatization of Propane over La/HZSM 5 Catalyst

La/HZSM 5 zeolite catalysts for aromatization of propane were prepared by means of impregnation and ion exchange methods. The structure and acidity of the catalysts were investigated with XRD, XPS, FT IR, NH 3 TPD technologies. The behavior of catalyst is obviously improved when La is introduced into HZSM 5. Especially, under conditions of 550 ℃, 600 h -1 , propane conversion and aromatics selectivity over La Z E reach 94 58%, 68 99%, respectively. FT IR and NH 3 TPD results show that the amount of Brsted acid centers decrease, but Lewis acid centers increase in La modified HZSM 5 zeolite. A strong interaction between La species and zeolite is observed which might affect the structure of HZSM 5. The new Lewis acid centers are active for aromatization of propane.